Correlating Dendritic Morphology and Crystallographic Texture with Dynamic Mechanical and Tensile Properties of WAAM-Processed Inconel 718 Alloy

Inconel 718 walls were fabricated using Cold Metal Transfer-based Wire Arc Additive Manufacturing (CMT-WAAM) to study the correlations between dendritic morphology, crystallographic texture, and mechanical properties. A strong ⟨001⟩ fiber texture developed along the build direction, with the texture index increasing from 2.8 at the bottom to 5.3 at the top. Vertical specimens showed higher yield (760 ± 15 MPa) and tensile strengths (980 ± 20 MPa) than horizontal specimens (705 ± 18 and 910 ± 22 MPa). Schmid factor analysis of the {111} {110} slip system revealed values of 0.31 (vertical) and 0.44 (horizontal), explaining strength anisotropy. Microhardness decreased from 282 ± 8 HV0.5 at the base to 246 ± 10 HV0.5 at the top, correlating with primary dendrite arm spacing increasing from 4.2 to 8.9 µm and Laves phase enrichment from 2.1 to 5.3%. Dynamic mechanical testing revealed orientation-dependent damping, with horizontal specimens exhibiting a higher damping ratio (1.85 ± 0.08%) than vertical specimens (1.32 ± 0.06%) owing to the higher density of high-angle grain boundaries. These structure–property relationships establish WAAM as viable for Inconel 718 components; however, part orientation must be selected based on whether static strength or vibration damping is prioritized.